1. Field of the Invention
The present invention relates to an in-vivo image display apparatus and a receiving system for receiving image data acquired by a body-insertable apparatus and displaying the image data.
2. Description of the Related Art
In recent years, in the field of body-insertable apparatuses such as endoscopes, there have been proposed capsule endoscopes capable of imaging function and radio communication function. During an observation period after such a capsule endoscope is swallowed by a subject for observation (examination) until the endoscope is naturally excreted from his/her body (human body), the capsule endoscope travels inside the organs (in the body cavity), such as esophagus, stomach and small intestine, along with their peristaltic motion. While traveling, the capsule endoscope successively captures images at a predetermined rate with the imaging function.
During the observation period in which the capsule endoscope travels inside the organs, image data captured by the capsule endoscope in the body cavity are successively transmitted via radio to the outside of the subject's body with the radio communication function, and stored in a memory of an external receiver. By carrying a receiver having the radio communication function and memory function, the subject is allowed to act freely even during the observation period after swallowing the capsule endoscope until excreting it. For example, Japanese Patent Application Laid-open No. 2003-19111 discloses a conventional technology related to such a receiving system.
To receive image data from the capsule endoscope, a general receiver includes a plurality of antennas. The antennas are set in places outside the subject's body to receive image signals transmitted from the capsule endoscope. The receiver switches the antennas from one to another while selecting one of them with high signal strength to receive the image signals from the selected one. In the conventional technology, a receiver switches a plurality of antennas set outside a subject's body and locates a capsule endoscope, i.e., an image signal source, inside the subject's body based on the electric field strength of a signal received by each antenna.
After completion of the operation of the capsule endoscope to capture images, generally, image data stored in the memory of the receiver is transferred to a workstation or the like and the images are viewed afterward. However, there has been an increasing demand from doctors for real-time viewing of images of, for example, areas of concern as well as areas such as the esophagus and stomach through which a capsule endoscope passes in a short time and thus which can be diagnosed immediately. To meet the demand, a system has been proposed that is provided with a simple in-vivo image display apparatus capable of real-time image display based on radio signals received from a capsule endoscope.
One of the simplest conventional in-vivo image display apparatuses is configured to be electrically connectable to a receiver, and includes a small display unit and a signal processor. With this configuration, upon receipt of a signal via the receiver, the signal processor performs predetermined processing on the signal and, based on the signal, the display unit displays an image captured by a capsule endoscope.
Having checked the position of a swallowed capsule endoscope and determined that it has reached a target organ of a subject, a doctor or the like observes the organ, and sometimes allows the subject to go out around the hospital after the observation. In such a case, it is required to locate the present position of the capsule endoscope. Generally, a doctor can recognize the intra-subject position of a capsule endoscope by checking an image received by an in-vivo image display apparatus. Besides, for example, when capsule endoscopy is performed in a plurality of patients at the same time, a doctor is required to recognize the position of each capsule endoscope.